Comparison of heuristic and empirical approaches for estimating reference evapotranspiration from limited inputs in Iran

Shiri, Jalal; Nazemi, Amir Hossein; Sadraddini, Ali Ashraf; Landeras, Gorka; Kisi, Özgür; Fard, Ahmad Fakheri; Martí, Pau

doi:10.1016/j.compag.2014.08.007

Cited by 151 publications

(61 citation statements)

References 47 publications

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“…VAL3, VAL2, Copais and especially VAL3), provided better estimations. These models have shown very good performance using data from other case studies (Pan et al, 2011;Shiri et al, 2014;Kisi, 2014;Gao et al, 2015;Valipour, 2015a, c;Djaman et al, 2015Djaman et al, , 2016Djaman et al, , 2017Ahooghalandari et al, 2017), and their use is recommended instead of the P-T and H-S with readjusted coefficients when the only missing climatic parameter is wind speed.…”

Section: Observations Derived By the Application Of The H-s Radiationmentioning

confidence: 99%

High-resolution global grids of revised Priestley–Taylor and Hargreaves–Samani coefficients for assessing ASCE-standardized reference crop evapotranspiration and solar radiation

Aschonitis

Papamichail

Demertzi

et al. 2017

Earth Syst. Sci. Data

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Abstract. The objective of the study is to provide global grids (0.5 • ) of revised annual coefficients for the Priestley-Taylor (P-T) and Hargreaves-Samani (H-S) evapotranspiration methods after calibration based on the ASCE (American Society of Civil Engineers)-standardized Penman-Monteith method (the ASCE method includes two reference crops: short-clipped grass and tall alfalfa). The analysis also includes the development of a global grid of revised annual coefficients for solar radiation (R s ) estimations using the respective R s formula of H-S. The analysis was based on global gridded climatic data of the period 1950-2000. The method for deriving annual coefficients of the P-T and H-S methods was based on partial weighted averages (PWAs) of their mean monthly values. This method estimates the annual values considering the amplitude of the parameter under investigation (ET o and R s ) giving more weight to the monthly coefficients of the months with higher ET o values (or R s values for the case of the H-S radiation formula). The method also eliminates the effect of unreasonably high or low monthly coefficients that may occur during periods where ET o and R s fall below a specific threshold. The new coefficients were validated based on data from 140 stations located in various climatic zones of the USA and Australia with expanded observations up to 2016. The validation procedure for ET o estimations of the short reference crop showed that the P-T and H-S methods with the new revised coefficients outperformed the standard methods reducing the estimated root mean square error (RMSE) in ET o values by 40 and 25 %, respectively. The estimations of R s using the H-S formula with revised coefficients reduced the RMSE by 28 % in comparison to the standard H-S formula. Finally, a raster database was built consisting of (a) global maps for the mean monthly ET o values estimated by ASCE-standardized method for both reference crops, (b) global maps for the revised annual coefficients of the P-T and H-S evapotranspiration methods for both reference crops and a global map for the revised annual coefficient of the H-S radiation formula and (c) global maps that indicate the optimum locations for using the standard P-T and H-S methods and their possible annual errors based on reference values. The database can support estimations of ET o and solar radiation for locations where climatic data are limited and it can support studies which require such estimations on larger scales (e.g. country, continent, world). The datasets produced in this study are archived in the PANGAEA database (https://doi.org/10.1594/PANGAEA.868808) and in the ESRN database

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Section: Observations Derived By the Application Of The H-s Radiationmentioning

confidence: 99%

High-resolution global grids of revised Priestley–Taylor and Hargreaves–Samani coefficients for assessing ASCE-standardized reference crop evapotranspiration and solar radiation

Aschonitis

Papamichail

Demertzi

et al. 2017

Earth Syst. Sci. Data

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“…During the recent years, many researchers tried to calibrate the Hargreaves model (Gavilan et al, 2006;Tabari and Talaee, 2011;Berti et al, 2014;Shiri et al, 2014Shiri et al, , 2015Marti et al, 2015;Cobaner et al, 2016;Xu et al, 2016;Feng et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

The study of potential evapotranspiration in future periods due to climate change in west of Iran

Rajabi

Babakhani

2018

IJCCSM

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If you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information. About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation.*Related content and download information correct at time of download. Findings -In all five stations, in all three scenarios and in all three periods, ETP will increase. The highest ETP increase will occur in the A1B scenario and then in the A1 scenario. The lowest increase will occur in the B1 scenario. In the 2020 decade, the highest ETP increase in three scenarios will occur in Khorramabad and then Hamedan. Kermanshah, Sanandaj and Ilam stations come at third to fifth place, respectively, with a close increase in amount. In the 2050 decade, ETP increase percentages in all scenarios are close to each other in all the five stations. In the 2080 decade, ETP increase percentages in all scenarios will be close to each other in four stations, namely, Kermanshah, Sanandaj, Khorramabad and Hamedan, and Ilam station will have a higher increase compared with the other four stations.Originality/value -Meanwhile, the highest ETP increase will occur in hot months of the year, which are significant with regard to irrigation and water resources.

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“…Vários métodos para estimar a ET 0 têm sido desenvolvidos e utilizados por pesquisadores e profissionais de acordo com a disponibilidade de dados meteorológicos históricos e atuais (BENLI et al, 2010;LUO et al, 2012;KISI, 2014), sendo que, a aplicação de um método específico para a estimativa de ET o geralmente depende da disponibilidade de dados no local de estudo (SHIRI et al, 2014). Ainda na escolha de um método para estimativa da ET 0 , devem ser consideradas a praticidade e a precisão da metodologia a ser utilizada, visto que, apesar dos métodos teóricos e micrometeorológicos serem baseados em princípios físicos, eles também apresentam limitações, sobretudo quanto à precisão instrumental, o que pode restringir a sua utilização (SILVA et al, 2015b).…”

Section: Introductionunclassified

Estimativa da Evapotranspiração de Referência Padrão (Penman-Monteith FAO 56): Uma Abordagem com Dados Meteorológicos Limitados

Silva¹

2016

NATIVA

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RESUMO:A agricultura irrigada é uma atividade que demanda grandes volumes de água. Neste sentido, o conhecimento das necessidades hídricas das culturas (evapotranspiração da cultura, ETc) assume fundamental importância no volume de água a ser aplicado. A ETc pode ser estimada a partir da evapotranspiração de referência (ET o ) e do coeficiente da cultura (Kc). Vários métodos para estimar a ET o têm sido desenvolvidos e utilizados por pesquisadores e profissionais de acordo com a disponibilidade de dados meteorológicos. A Organização das Nações Unidas para Alimentação e Agricultura (FAO) recomenda o método de Penman-Monteith (PM-FAO 56) como padrão. Porém, este método requer um grande número de dados de entrada como radiação solar, temperatura do ar, velocidade do vento e umidade relativa, que em muitos locais muitas vezes não estão disponíveis. Métodos foram sugeridos para estimativa de dados em falta, como a radiação, o déficit de pressão de vapor e a velocidade do vento. No presente artigo é feito uma revisão de literatura de trabalhos sobre estimativas de ET o PM-FAO 56 com dados meteorológicos limitados, em diferentes condições climáticas. Conclui-se que a velocidade do vento fixa de 2,0 m s -1 teve maior efeito na redução da precisão das estimativas de ETo. Palavras-chave: manejo da irrigação, temperatura do ar, velocidade do vento. Estimation of reference evapotranspiration by FAO-56 Penman-Monteith:An approach with limited weather data ABSTRACT: Irrigated agriculture is an activity that requires large water volumes. In this sense, knowledge of crop water requirements (crop evapotranspiration, ETc) is important in the water volume to be applied. The ETc can be estimated from the reference evapotranspiration (ET o ) and crop coefficient (Kc). Several methods to estimate ET o have been developed and used by researchers and professionals according to availability of weather data. The Food and Agricultural Organization of the United Nations (FAO) recommends as standard method Penman-Monteith (FAO-56 PM). However, this method requires a large number of input data such as solar radiation, air temperature, relative humidity and wind speed, which in many locations often are not available. Methods have been suggested to estimate missing data, such as radiation, vapor pressure deficit and wind speed. This paper is a literature review work of ET o FAO-56 PM estimates with limited weather data in different climatic conditions. It can be concluded that fixed wind speed of 2.0 m s -1 had greater effect with reduced accuracy of ETo estimates.

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Comparison of heuristic and empirical approaches for estimating reference evapotranspiration from limited inputs in Iran

Cited by 151 publications

References 47 publications

High-resolution global grids of revised Priestley–Taylor and Hargreaves–Samani coefficients for assessing ASCE-standardized reference crop evapotranspiration and solar radiation

High-resolution global grids of revised Priestley–Taylor and Hargreaves–Samani coefficients for assessing ASCE-standardized reference crop evapotranspiration and solar radiation

The study of potential evapotranspiration in future periods due to climate change in west of Iran

Estimativa da Evapotranspiração de Referência Padrão (Penman-Monteith FAO 56): Uma Abordagem com Dados Meteorológicos Limitados

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